Quote (Skitty @ 14 Jan 2010 22:11)
"+ % Heal Mastery Increases the effectiveness of any healing charms you use by the % listed. At the time of this writing, the stats visible on the heal charm will not change, however."
^ From the LS Portal.
Heal Master makes you heal for a higher amount. It doesn't increase the Proficiency EXP. It works for all Heal Charm types though.
kk thx man